Semiconductor device

ABSTRACT

Disclosed is a semiconductor device comprising a substrate, a first dielectric layer on the substrate, a first lower conductive line in the first dielectric layer, an etch stop layer on the first dielectric layer, a via-structure that penetrates the etch stop layer and connects to the first lower conductive line, a second dielectric layer on the etch stop layer, and an upper conductive line that penetrates the second dielectric layer and connects to the via-structure. The first dielectric layer includes a dielectric pattern at a level higher than a top surface of the first lower conductive line. The upper conductive line is in contact with a top surface of the etch stop layer. The etch stop layer has at an upper portion a rounded surface in contact with the via-structure.

CROSS-REFERENCE TO RELATED APPLICATION

This U.S. nonprovisional application claims priority under 35 U.S.0 §119 to Korean Patent Application No. 10-2019-0078599 filed on Jul. 1,2019 in the Korean Intellectual Property Office, the entire contents ofwhich are hereby incorporated by reference.

BACKGROUND

The present inventive concepts relate to a semiconductor device. Moreparticularly, the present inventive concepts relate to a semiconductordevice whose etch stop layer includes a rounded surface.

Semiconductor devices are widely used in the electronics industrybecause of their small size, multi-functionality, and/or lowmanufacturing cost. Semiconductor devices may encompass memory devicesfor storing data, logic devices for processing data, and hybrid devicesfor operating various functions contemporaneously or simultaneously.

With new developments and advancements in the electronics industry,smaller semiconductor devices have been increasingly. However, it isincreasingly difficult to manufacture semiconductor devices becausedefining fine patterns within the process margin in an exposure processincreases in difficulty as the devices grow smaller. Higher speedsemiconductor devices have also been increasingly required with theadvancement of the electronic industry. Various structures have beenstudied to find solutions for the growing need for high integrationand/or high-speed semiconductor devices while still maintainingreliability.

SUMMARY

According to some example embodiments, a semiconductor device maycomprise: a substrate; a first dielectric layer on the substrate; afirst lower conductive line in the first dielectric layer; an etch stoplayer on the first dielectric layer; a via-structure that penetrates theetch stop layer and connects to the first lower conductive line; asecond dielectric layer on the etch stop layer; and an upper conductiveline that penetrates the second dielectric layer and connects to thevia-structure. The first dielectric layer may include a dielectricpattern at a level higher than a top surface of the first lowerconductive line. The upper conductive line may be in contact with a topsurface of the etch stop layer. The etch stop layer may have at an upperportion with a rounded surface in contact with the via-structure.

According to some example embodiments, a semiconductor device maycomprise: a substrate; a first dielectric layer on the substrate; afirst lower conductive line, a second lower conductive line, and a thirdlower conductive line that are sequentially arranged in a firstdirection in the first dielectric layer; an etch stop layer on the firstdielectric layer; a via-structure that penetrates the etch stop layerand connects to the second lower conductive line; a second dielectriclayer on the etch stop layer; and an upper conductive line thatpenetrates the second dielectric layer and connects to thevia-structure. The first dielectric layer may include a plurality ofdielectric patterns at a level higher than top surfaces of the first,second, and third lower conductive lines. The upper conductive line maybe in contact with a top surface of the etch stop layer. The etch stoplayer may include a first etch stop pattern that conformally covers thefirst dielectric layer, a second etch stop pattern on the first etchstop pattern, and a third etch stop pattern on the second etch stoppattern. The third etch stop pattern may have a rounded surface incontact with the via-structure.

According to some example embodiments, a semiconductor device maycomprise: a substrate; a first dielectric layer on the substrate; afirst lower conductive line in the first dielectric layer; an etch stoplayer on the first dielectric layer; a via-structure that penetrates theetch stop layer and connects to the first lower conductive line; asecond dielectric layer on the etch stop layer; and an upper conductiveline in the second dielectric layer and connected to the via-structure.The first dielectric layer may include a dielectric pattern at a levelhigher than a level of the first lower conductive line. The seconddielectric layer may include an insert segment between the upperconductive line and the etch stop layer. The insert segment may have arounded surface in contact with the via-structure. The etch stop layermay have a rounded surface in contact with the via-structure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a plan view showing a semiconductor device accordingto some example embodiments.

FIG. 2A illustrates a cross-sectional view taken along line A-A′ of FIG.1.

FIG. 2B illustrates a cross-sectional view taken along line B-B′ of FIG.1.

FIGS. 3A, 3B, 3C, and 3D illustrate cross-sectional views showing amethod of fabricating a semiconductor device according to some exampleembodiments.

FIGS. 4, 5, 6, 7, 8, 9, and 10 illustrate cross-sectional views showinga semiconductor device according to some example embodiments.

DETAILED DESCRIPTION OF EMBODIMENTS

Although the terms “first,” “second,” “third,” etc., may be used hereinto describe various elements, components, regions, layers, and/orsections, these elements, components, regions, layers, and/or sections,should not be limited by these terms. These terms are only used todistinguish one element, region, layer, or section, from anotherelement, region, layer, or section. Thus, a first element, component,region, layer, or section, discussed below may be termed a secondelement, component, region, layer, or section, without departing fromthe scope of this disclosure.

Spatially relative terms, such as “below,” “lower,” “upper,” “top,” andthe like, may be used herein for ease of description to describe oneelement or feature's relationship to another element(s) or feature(s) asillustrated in the figures. It will be understood that the spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. For example, if the device in the figures is turned over,elements described as “below” other elements or features would then beoriented “above” the other elements or features. Thus, the example terms“below” may encompass both an orientation of above and below. The devicemay be otherwise oriented and the spatially relative descriptors usedherein interpreted accordingly.

FIG. 1 illustrates a plan view showing a semiconductor device accordingto some example embodiments. FIG. 2A illustrates a cross-sectional viewtaken along line A-A′ of FIG. 1. FIG. 2B illustrates a cross-sectionalview taken along line B-B′ of FIG. 1.

Referring to FIGS. 1, 2A, and 2B, a first dielectric layer 210 may be ona substrate 100. The substrate 100 may be a semiconductor substrate. Forexample, the substrate 100 may be a silicon substrate, a germaniumsubstrate, or a silicon-germanium substrate. The substrate 100 may havetransistors and/or memory cells formed thereon. The first dielectriclayer 210 may be an electrical insulator. For example, the firstdielectric layer 210 may be a silicon oxide layer, a silicon oxynitridelayer, or a combination thereof.

First, second, and third lower conductive lines LCL1, LCL2, and LCL3 maybe imbedded the first dielectric layer 210. Each of the first, second,and third lower conductive lines LCL1, LCL2, and LCL3 may beelectrically connected to transistors and/or memory cells in thesubstrate 100. Each of the first, second, and third lower conductivelines LCL1, LCL2, and LCL3 may have a bar or linear shape that extendsin a first direction D1. The first direction D1 may be parallel to a topsurface of the substrate 100. The first, second, and third lowerconductive lines LCL1, LCL2, and LCL3 may be spaced apart from eachother in a second direction D2. For example, the first, second, andthird lower conductive lines LCL1, LCL2, and LCL3 may be sequentiallyarranged along the second direction D2. The second direction D2 may beparallel to the top surface of the substrate 100 and may intersect thefirst direction D1. A third direction D3 may be perpendicular to the topsurface of the substrate 100.

Each of the first, second, and third lower conductive lines LCL1, LCL2,and LCL3 may include a barrier layer BA and a metal line ME. The barrierlayer BA may conformally cover sidewalls and a bottom surface of themetal line ME. The barrier layers BA may include a chemically stablemetal or composite, for example, Ta, TaN, Ti, TiN, or a combinationthereof. The metal lines ME may include a conductive metal, for example,Cu, W, Al, Co, or alloys thereof.

The first dielectric layer 210 may include dielectric patterns 211. Thedielectric patterns 211 may be patterned in an upper portion of thefirst dielectric layer 210. The dielectric patterns 211 may be definedto refer to portions of the first dielectric layer 210 that are locatedat a higher level than those of the top surfaces of the first, second,and third lower conductive lines LCL1, LCL2, and LCL3. The dielectricpatterns 211 may extend in the first direction D1. The dielectricpatterns 211 may be sequentially arranged along the second direction D2.For example, the dielectric patterns 211 may be spaced apart from eachother in the second direction D2.

First, second, and third trenches TR1, TR2, and TR3 may be defined bysidewalls of the dielectric patterns 211 and the top surfaces of thefirst, second, and third lower conductive lines LCL1, LCL2, and LCL3respectively. For example, the first trench TR1 may be provided on thefirst lower conductive line LCL1, the second trench TR2 may be providedon the second lower conductive line LCL2, and the third trench TR3 maybe provided on the third lower conductive line LCL3. The first, second,and third trenches TR1, TR2, and TR3 may extend in the first directionD1. The first, second, and third trenches TR1, TR2, and TR3 may besequentially arranged along the second direction D2. Each of the first,second, and third trenches TR1, TR2, and TR3 may be provided between twodielectric patterns 211. The first, second, and third trenches TR1, TR2,and TR3 may have the same width in the second direction D2. A firstwidth W1 may be defined as the width in the second direction D2 of eachof the first, second, and third trenches TR1, TR2, and TR3.

Sidewalls 211 b of the dielectric patterns 211 adjacent to the secondlower conductive line LCL2 may incline relative to the top surface ofthe substrate 100, thus having a slope relative to the plane of the topsurface of the substrate 100.

An etch stop layer ESL may be on the first dielectric layer 210. Theetch stop layer ESL may cover the first dielectric layer 210 and thefirst, second, and third lower conductive lines LCL1, LCL2, and LCL3.

The etch stop layer ESL may include a first etch stop pattern 230, asecond etch stop pattern 240, and a third etch stop pattern 250.

The first etch stop pattern 230 may conformally cover the firstdielectric layer 210 and the top surfaces of the first, second, andthird lower conductive lines LCL1, LCL2, and LCL3. The first etch stoppattern 230 may partially fill the first, second, and third trenchesTR1, TR2, and TR3.

The first etch stop pattern 230 may include a lower layer 231 and anupper layer 232. Each of the lower and upper layers 231 and 232 may havea uniform thickness. The thickness of the lower layer 231 may be lessthan that of the thickness of the upper layer 232. The lower layer 231may include an aluminum-based ceramic, for example, one or more of AlOx,AlN, and AlOC. The upper layer 232 may include a silicon-based ceramic,for example, one or more of SiOC and SiCN. The thickness of the upperlayer 232 may be two to four times the thickness of the lower layer 231.For example, the thickness of the lower layer 231 may be about 10 Å, andthe thickness of the upper layer 232 may be about 30 Å.

A first thickness T1 may be defined as a thickness of the first etchstop pattern 230. Double the first thickness T1 may be less than thefirst width W1. Therefore, the first etch stop pattern 230 may notcompletely fill the first, second, and third trenches TR1, TR2, and TR3.

The second etch stop pattern 240 may be on the first etch stop pattern230. The second etch stop pattern 240 may include a base segment 241that also extends in the second direction D2 and filling segments 242that protrude from the base segment 241 toward the substrate 100. Thefirst and third trenches TR1 and TR3 may be filled with the fillingsegments 242. The second trench TR2 may be filled with the fillingsegments 242 and a via-structure VA which will be discussed below. Thesecond etch stop pattern 240 may include silicon-carbon based ceramics,for example, one or more of SiOC, SiCN, and SiCOH. The second etch stoppattern 240 may be comprised of the same material elements to those ofthe upper layer 232 of the first etch stop pattern 230, for example,SiOC and SiCN. However, the composition of the second etch stop pattern240 may be different from that of the composition of the upper layer 232of the first etch stop pattern 230.

The first and second etch stop patterns 230 and 240 may have flatsidewalls. The flat sidewalls of the first and second etch stop patterns230 and 240 may be perpendicular to a top surface of the dielectriclayer 210. The flat sidewalls may be in contact with a via-structure VA,which will be discussed below.

The third etch stop pattern 250 may be conformally on the second etchstop pattern 240. The third etch stop pattern 250 may also extend in thesecond direction D2. For example, the third etch stop pattern 250 mayextend parallel to the top surface of the substrate 100. The third etchstop pattern 250 may include one or more aluminum ceramic materials, forexample, AlOx, AN, and AlOC. The third etch stop pattern 250 may have athickness of, for example, about 15 Å to about 30 Å.

A hole HO may be defined by the space contained between the top surfaces211 a of the dielectric patterns 211 and the sidewall ESLS of the etchstop layer ESL. The hole HO may be provided on the second trench TR2.The hole HO may connect to the second trench TR2. The hole HO may have awidth in the second direction D2 greater than a width in the seconddirection D2 of the second trench TR2. A thickness in the firstdirection D1 of the hole HO may be similar to the thickness in thesecond direction D2 of the hole HO. The hole HO may penetrate the etchstop layer ESL.

The third etch stop pattern 250 may have a rounded surface 251. Therounded surface 251 of the third etch stop pattern 250 may connect a topsurface 252 of the third etch stop pattern 250 to a sidewall of thesecond etch stop pattern 240, thus transitioning from the top surface252 of the third etch stop pattern 250 to the flat sidewall ESLS of theetch stop layer ESL. The rounded surface 251 of the third etch stoppattern 250 may be in contact with a via-structure VA which will bediscussed below. The rounded surface 251 may be defined as top cornerrounding (TCR).

A second dielectric layer 260 may be provided on the third etch stoppattern 250. The second dielectric layer 260 may be formed of a low-kdielectric layer having a low dielectric constant of about 2.2 to about3.0. For example, the second dielectric layer 260 may include SiCOH.

A fourth trench TR4 may be in the second dielectric layer 260. Thefourth trench TR4 may be defined by the space between a sidewall of thesecond dielectric layer 260 and the top surface 252 of the third etchstop pattern 250. The fourth trench TR4 may be on the hole HO and may beconnected to the hole HO. The fourth trench TR4 may have a width in thesecond direction D2 greater than the width in the second direction D2 ofthe hole HO. The fourth trench TR4 may extend in the first direction D1.

A via-structure VA may be provided to fill the hole HO and a portion ofthe second trench TR2. The via-structure VA may penetrate the etch stoplayer ESL. The via-structure VA may be electrically connected to thesecond lower conductive line LCL2. The via-structure VA may include afirst segment VA1 that fills the hole HO and a second segment VA2 thatfills a portion of the second trench TR2. A width in the seconddirection D2 of the first segment VA1 may be greater than a width in thesecond direction D2 of the second segment VA2.

The first segment VA1 of the via-structure VA may be in contact with thesidewall ESLS of the etch stop layer ESL and with the top surfaces 211 aof the dielectric patterns 211. The first segment VA1 may have asidewall in contact with the sidewall ESLS of the etch stop layer ESLand a bottom surface in contact with the top surfaces 211 a of thedielectric patterns 211. The first segment VA1 of the via-structure VAmay have a rounded sidewall along the rounded surface 251 of the thirdetch stop pattern 250.

The second segment VA2 of the via-structure VA may be in contact withthe sidewalls 211 b of the dielectric patterns 211 adjacent to thesecond lower conductive line LCL2 and with the top surface of the secondlower conductive line LCL2. The second segment VA2 may have a sidewallin contact with the sidewall 211 b of the dielectric pattern 211 and abottom surface in contact with the top surface of the second lowerconductive line LCL2.

An upper conductive line UCL may fill the fourth trench TR4. The upperconductive line UCL may penetrate the second dielectric layer 260 andmay contact a top surface of the etch stop layer ESL. For example, theupper conductive line UCL may have a bottom surface UCLB in contact withthe top surface 252 of the third etch stop pattern 250. The upperconductive line UCL may be electrically connected through thevia-structure VA to the second lower conductive line LCL2. Similar tothe first, second, and third lower conductive lines LCL1, LCL2, andLCL3, the upper conductive line UCL and the via-structure VA may eachinclude a metal line ME and a barrier layer BA. The via-structure VA andthe upper conductive line UCL may be segments of a structure that areformed at the same time, as discussed in the following fabricationmethod.

A first capping layer 270 may be provided to cover the second dielectriclayer 260 and the upper conductive line UCL. The first capping layer 270may include an aluminum-based ceramic, for example, one or more of AlOx,AN, and AlOC.

A second capping layer 280 may be provided on the first capping layer270. The second capping layer 280 may include a silicon-carbon basedceramic, for example, one or more of SiOC and SiCN.

FIGS. 3A, 3B, 3C, and 3D illustrate cross-sectional views showing amethod of fabricating a semiconductor device according to some exampleembodiments of the present inventive concepts.

Referring to FIG. 3A, a first dielectric layer 210 may be formed on asubstrate 100, and first, second, and third lower conductive lines LCL1,LCL2, and LCL3 may be formed in the first dielectric layer 210.

For example, the formation of the first, second, and third lowerconductive lines LCL1, LCL2, and LCL3 may include forming in the firstdielectric layer 210 trenches to partially expose a top surface of thesubstrate 100, conformally forming a barrier material to cover the firstdielectric layer 210 and the substrate 100, forming a metallic materialon the barrier material, performing a planarization process in which thebarrier material and the metallic material are partially removed toexpose a top surface of the first dielectric layer 210, and partiallyremoving the metallic material and the barrier material from thetrenches to form the first, second, and third lower conductive linesLCL1, LCL2, and LCL3. The removal of the metallic material and thebarrier material from the trenches may define dielectric patterns 211 inan upper portion of the first dielectric layer 210.

For another example, the formation of the first, second, and third lowerconductive lines LCL1, LCL2, and LCL3 may include forming in the firstdielectric layer 210 trenches to partially expose the top surface of thesubstrate 100, conformally forming a barrier material to cover the firstdielectric layer 210 and the substrate 100, forming a metallic materialon the barrier material, performing a planarization process in which thebarrier material, the metallic material, and the first dielectric layer210 are partially removed to form the first, second, and third lowerconductive lines LCL1, LCL2, and LCL3, and forming the dielectricpatterns 211 on the first dielectric layer 210.

As shown above, the first, second, and third trenches TR1, TR2, and TR3may be formed as part of the formation of the first, second, and thirdlower conductive lines LCL1, LCL2, and LCL3.

Referring to FIG. 3B, a first preliminary layer 230 a may be formed. Thefirst preliminary layer 230 a may include a lower preliminary layer 231a and an upper preliminary layer 232 a. The first preliminary layer 230a may be formed to conformally cover the first dielectric layer 210 andthe first, second, and third lower conductive lines LCL1, LCL2, andLCL3.

A first thickness T1 may be defined to indicate a thickness of the firstpreliminary layer 230 a. A first width W1 may be defined to indicate awidth in a second direction D2 of each of the first, second, and thirdtrenches TR1, TR2, and TR3. A double of the first thickness T1 may beless than the first width W1. Thus, the first preliminary layer 230 amay not completely fill the first, second, and third trenches TR1, TR2,and TR3.

Referring to FIG. 3C, a second preliminary layer 240 a may be formed onthe first preliminary layer 230 a. The second preliminary layer 240 amay be formed, for example, by a flowable chemical vapor deposition(FCVD) process, a spin-on-glass (SOG) process, or a plasma enhancedchemical vapor deposition (PECVD) process.

The second preliminary layer 240 a may include a base segment 241 a thatextends in the second direction D2 and filling segments 242 a thatprotrude from the base segment 241 a toward the substrate 100. Thefirst, second, and third trenches TR1, TR2, and TR3 may be completelyfilled with the filling segments 242 a. The base segment 241 a may beformed on the filling segments 242 a.

The formation of the second preliminary layer 240 a may includeperforming a planarization process to reduce the thickness of the basesegment 241 a. Alternatively, the formation of the second preliminarylayer 240 a may not include the planarization process. Even when noplanarization process is performed, the second preliminary layer 240 amay have a flat top surface.

Referring to FIG. 3D, a third preliminary layer 250 a may be formed onthe second preliminary layer 240 a. Referring back to FIGS. 2A and 2B, asecond dielectric layer 260 may be formed on the third preliminary layer250 a. A fourth trench TR4 and a hole HO may be formed, and the secondtrench TR2 may be opened again at its portion below the hole HO. Thefourth trench TR4 may be formed by patterning the second dielectriclayer 260. The third preliminary layer 250 a may serve as an etch stoplayer when the second dielectric layer 260 is patterned. The hole HO maybe formed by patterning the first, second, and third preliminary layers230 a, 240 a, and 250 a. When the hole HO is formed, the first, second,and third preliminary layers 230 a, 240 a, and 250 a may be patternedinto first, second, and third etch stop patterns 230, 240, and 250. Theformation of the hole HO may include patterning the third preliminarylayer 250 a by using the second preliminary layer 240 a as an etch stoplayer, and patterning the first and second preliminary layers 230 a and240 a. When the first and second preliminary layers 230 a and 240 a arepatterned, a rounded surface 251 may be formed on the third etch stoppattern 250.

A portion of the second trench TR2 may be opened again due to theremoval of the second preliminary layer 240 a and the first preliminarylayer 230 a that partially fill the second trench TR2 below the hole HO.When the portion of the second trench TR2 is opened again, exposedsidewalls 211 b of the dielectric patterns 211 may have slopes relativeto the top surface of the substrate 100.

A via-structure VA and an upper conductive line UCL may be formed. Theformation of the via-structure VA and the upper conductive line UCL mayinclude conformally forming a barrier material on an entire surface ofthe substrate 100, forming a metallic material on the barrier material,and performing a planarization process to partially remove the barrierand metallic materials.

Because the rounded surface 251 is formed on the third etch stop pattern250, a sufficient fill margin may be obtained while the via-structure VAis formed.

A first capping layer 270 may be formed to cover the upper conductiveline UCL and the second dielectric layer 260. A second capping layer 280may be formed on the first capping layer 270.

FIGS. 4, 5, 6, 7, 8, 9, and 10 illustrate cross-sectional views showinga semiconductor device according to some example embodiments of thepresent inventive concepts. Except for the following description, theaforementioned discussion related to the semiconductor device of FIGS.1, 2A, and 2B is identically or similarly applicable to the embodimentsbelow.

Referring to FIG. 4, a semiconductor device according to an exampleembodiment may be configured such that the upper conductive line UCL maybe spaced apart from the third etch stop pattern 250. The seconddielectric layer 260 may include an insert segment 261 below the upperconductive line UCL. The insert segment 261 may be interposed betweenthe upper conductive line UCL and the top surface 252 of the third etchstop pattern 250. The insert segment 261 may have a rounded surface 261a in contact with the first segment VA1 of the via-structure VA.

Referring to FIG. 5, a semiconductor device according to an exampleembodiment may be configured such that the third etch stop pattern 250may include an insert segment 253. The insert segment 253 may bedisposed below the upper conductive line UCL.

The bottom surface UCLB of the upper conductive line UCL may be locatedat a lower level than that of the top surface 252 of the third etch stoppattern 250. The insert segment 253 may have a top surface at a lowerlevel than that of the top surface 252. The top surface 252 maycorrespond to an uppermost surface of the third etch stop pattern 250.The insert segment 253 may have a rounded surface 253 a in contact withthe first segment VA1 of the via-structure VA.

Referring to FIG. 6, a semiconductor device according to an exampleembodiment may be configured such that the first etch stop pattern 230is formed of a single layer. The first etch stop pattern 230 in thesemiconductor device according to an example embodiment may be the sameas the lower layer 231 of the first etch stop pattern 230 in thesemiconductor device discussed above with reference to FIGS. 1, 2A, and2B.

In the semiconductor device according to an example embodiment, thesecond etch stop pattern 240 may include the base segment 241 thatextends in the second direction D2 and the filling segment 242 thatprotrudes from the base segment 241 toward the substrate 100.

In the semiconductor device according to an example embodiment, thesecond etch stop pattern 240 may be formed by a single precursoractivated radical chemistry (SPARC) process.

Referring to FIG. 7, a semiconductor device according to an exampleembodiment may be configured such that the second etch stop pattern 240may not include the base segment 241 of the semiconductor devicediscussed above with reference to FIGS. 1, 2A, and 2B. In thesemiconductor device according to an example embodiment, the second etchstop pattern 240 may have a top surface coplanar with that of the topsurface of the first etch stop pattern 230. When a planarization processis performed on the second preliminary layer 240 a as discussed in FIG.3C, the base segment 241 a of the second preliminary layer 240 a may becompletely removed to form the second etch stop pattern 240 according tothe present inventive concepts.

The third etch stop pattern 250 may be in contact with the first andsecond etch stop patterns 230 and 240.

The second dielectric layer 260 may include an insert segment 261disposed below the upper conductive line UCL.

Referring to FIG. 8, a semiconductor device according to an exampleembodiment may be configured such that the third etch stop pattern 250may include a protrusion 254. The protrusion 254 may protrude in adirection toward the substrate 100 from a bottom surface of the thirdetch stop pattern 250. The protrusion 254 may be partially penetrate thesecond etch stop pattern 240. The protrusion 254 may have a lowermostportion in the filling segment 242 of the second etch stop pattern 240.

Referring to FIG. 9, a semiconductor device according to an exampleembodiment may be configured such that an active pattern AP may bedefined on an upper portion of the substrate 100. The substrate 100 maybe a semiconductor substrate, for example, a silicon substrate, agermanium substrate, or a silicon-germanium substrate. Source/drainpatterns SD may be in the active pattern AP. The source/drain patternsSD may include a semiconductor material doped with p-type or n-typeimpurities. Gate spacers GS, gate dielectric layers GI, gate electrodesGE, and gate capping patterns CP may be on the active pattern AP. Thegate electrode GE may be between two gate spacers GS. The gatedielectric layer GI may cover a bottom surface and a sidewall of thegate electrode GE. The gate capping pattern CP may cover the topsurfaces of the gate spacers GS, a top surface of the gate dielectriclayer GI, and a top surface of the gate electrode GE.

A first lower dielectric layer 110 may cover the source/drain patternsSD. A second lower dielectric layer 120 may cover the first lowerdielectric layer 110 and the gate capping patterns CP.

Contacts CT may penetrate the first and second lower dielectric layers110 and 120 and to have connection with corresponding source/drainpatterns SD.

The first dielectric layer 210 may be on the second lower dielectriclayer 120.

The first, second, and third lower conductive lines LCL1, LCL2, and LCL3may be embedded in the first dielectric layer 210. The first, second,and third lower conductive lines LCL1, LCL2, and LCL3 may be areconnected to corresponding contacts CT.

The etch stop layer ESL may be on the first dielectric layer 210. Thevia-structure VA and the upper conductive line UCL may be on the secondlower conductive line LCL2.

The second dielectric layer 260 may be on the etch stop layer ESL, thefirst capping layer 270 may be on the second dielectric layer 260, andthe second capping layer 280 may be on the first capping layer 270.

Referring to FIG. 10, a semiconductor device according to an exampleembodiment may be configured such that the first segment VA1 of thevia-structure VA may have a first sidewall VA1S1 and a second sidewallVA1S2. The first sidewall VA may be parallel to the third direction D3.For example, the first sidewall VA1S1 may be perpendicular to the topsurface of the substrate 100. The second sidewall VA1S2 may have a sloperelative to the first sidewall VA1S1. For example, the second sidewallVA1S2 may have a slope relative to the top surface of the substrate 100.The second segment VA2 of the via-structure VA may only partially fillthe second trench TR2. For example, the second segment VA2 of thevia-structure VA may not completely fill the second trench TR2. The etchstop layer ESL may fill a portion of the second trench TR2, whichportion is not filled with the second segment VA2 of the via-structureVA.

The second segment VA2 of the via-structure VA may have a third sidewallVA2S1 and a fourth sidewall VA2S2. The third sidewall VA2S1 may have aslope relative to the top surface of the substrate 100. The thirdsidewall VA2S1 may be in contact with a sidewall of the dielectricpattern 211, which sidewall faces the third sidewall VA2S1. The fourthsidewall VA2S2 may have a slope relative to the top surface of thesubstrate 100. The fourth sidewall VA2S2 may be spaced apart from asidewall of the dielectric pattern 211. The etch stop layer ESL may filla space between the fourth sidewall VA2S2 and the facing sidewall of thedielectric pattern 211. The fourth sidewall VA2S2 may be coplanar withthe second sidewall VA1S2.

According to the present inventive concepts, a semiconductor device mayinclude an etch stop layer with a rounded surface, and thus thesemiconductor device may increase in via-fill margin.

Although the present invention has been described in connection withsome example embodiments of the present inventive concepts illustratedin the accompanying drawings, it will be understood to those skilled inthe art that various changes and modifications may be made withoutdeparting from the technical spirit and essential feature of the presentinventive concepts. It will be apparent to those skilled in the art thatvarious substitution, modifications, and changes may be thereto withoutdeparting from the scope and spirit of the inventive concepts.

What is claimed is:
 1. A semiconductor device, comprising: a substrate;a first dielectric layer on the substrate; a first lower conductive linein the first dielectric layer; an etch stop layer on the firstdielectric layer; a via-structure that penetrates the etch stop layerand is connected to the first lower conductive line; a second dielectriclayer on the etch stop layer; and an upper conductive line thatpenetrates the second dielectric layer and is connected to thevia-structure, wherein the first dielectric layer includes a dielectricpattern at a level higher than a top surface of the first lowerconductive line, wherein the upper conductive line is in contact with atop surface of the etch stop layer, and wherein the etch stop layer hasat an upper portion with a rounded surface in contact with thevia-structure.
 2. The semiconductor device of claim 1, wherein the etchstop layer includes: a first etch stop pattern; a second etch stoppattern on the first etch stop pattern; and a third etch stop pattern onthe second etch stop pattern.
 3. The semiconductor device of claim 2,wherein the third etch stop pattern has the rounded surface in contactwith the via-structure.
 4. The semiconductor device of claim 3, whereinthe first and second etch stop patterns have flat sidewalls in contactwith the via-structure.
 5. The semiconductor device of claim 2, whereinthe third etch stop pattern extends parallel to a top surface of thesubstrate and includes aluminum.
 6. The semiconductor device of claim 2,wherein the second etch stop pattern includes: a base segment thatextends parallel to a top surface of the substrate; and a fillingsegment that protrudes from the base segment toward the substrate. 7.The semiconductor device of claim 1, further comprising at least asecond lower conductive line in the first dielectric layer, wherein atrench is defined by a top surface of the second lower conductive lineand sidewalls of the dielectric pattern, and the etch stop layer fillsthe trench.
 8. The semiconductor device of claim 7, wherein the etchstop layer includes: a first etch stop pattern that conformally coversthe trench; and a second etch stop pattern that fills the trench.
 9. Thesemiconductor device of claim 8, wherein double of a thickness of thefirst etch stop pattern is less than a width of the trench.
 10. Thesemiconductor device of claim 1, wherein the via-structure includes: afirst segment in contact with a sidewall of the etch stop layer and atop surface of the dielectric pattern; and a second segment in contactwith a sidewall of the dielectric pattern and the top surface of thefirst lower conductive line.
 11. A semiconductor device, comprising: asubstrate; a first dielectric layer on the substrate; a first lowerconductive line, a second lower conductive line, and a third lowerconductive line that are sequentially arranged in a first direction inthe first dielectric layer; an etch stop layer on the first dielectriclayer; a via-structure that penetrates the etch stop layer and connectsto the second lower conductive line; a second dielectric layer on theetch stop layer; and an upper conductive line that penetrates the seconddielectric layer and connects to the via-structure, wherein the firstdielectric layer includes a plurality of dielectric patterns at a levelhigher than top surfaces of the first, second, and third lowerconductive lines, wherein the upper conductive line contacts a topsurface of the etch stop layer, and wherein the etch stop layerincludes: a first etch stop pattern that conformally covers the firstdielectric layer; a second etch stop pattern on the first etch stoppattern; and a third etch stop pattern on the second etch stop pattern,the third etch stop pattern has a rounded surface in contact with thevia- structure.
 12. The semiconductor device of claim 11, wherein thesecond etch stop pattern includes: a base segment that extends in thefirst direction; and a filling segment that protrudes from the basesegment toward the substrate.
 13. The semiconductor device of claim 11,wherein the third etch stop pattern includes an insert segment below theupper conductive line, and a top surface of the insert segment islocated at a level lower than a top surface of the third etch stoppattern.
 14. The semiconductor device of claim 13, wherein the secondetch stop pattern has a rounded surface in contact with thevia-structure.
 15. The semiconductor device of claim 11, wherein thethird etch stop pattern includes a protrusion that protrudes towards thesubstrate.
 16. A semiconductor device, comprising: a substrate; a firstdielectric layer on the substrate; a first lower conductive line in thefirst dielectric layer; an etch stop layer on the first dielectriclayer; a via-structure that penetrates the etch stop layer and isconnected to the first lower conductive line; a second dielectric layeron the etch stop layer; and an upper conductive line in the seconddielectric layer and connected to the via-structure, wherein the firstdielectric layer includes a dielectric pattern at a level higher than atop surface of the first lower conductive line, the second dielectriclayer includes an insert segment between the upper conductive line andthe etch stop layer, the insert segment has a rounded surface in contactwith the via-structure, and the etch stop layer has a rounded surface incontact with the via-structure.
 17. The semiconductor device of claim16, wherein the via-structure includes: a first segment in contact witha sidewall of the etch stop layer and a top surface of the dielectricpattern; and a second segment in contact with a sidewall of thedielectric pattern and the top surface of the first lower conductiveline.
 18. The semiconductor device of claim 16, further comprising asecond lower conductive line in the first dielectric layer, wherein atrench is defined by a top surface of the second lower conductive lineand sidewalls of the dielectric pattern, and the etch stop layer fillsthe trench.
 19. The semiconductor device of claim 18, wherein the etchstop layer includes: a first etch stop pattern that conformally coversthe trench; and a second etch stop pattern that fills the trench,wherein a top surface of the first etch stop pattern is coplanar with atop surface of the second etch stop pattern.
 20. The semiconductordevice of claim 19, wherein the etch stop layer further includes a thirdetch stop pattern in contact with the first and second etch stoppatterns, the first etch stop pattern has a flat sidewall in contactwith the upper conductive line, and the third etch stop pattern has arounded surface in contact with the via-structure.